// Copyright (c) 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_ANDROID_URL_REQUEST_CONTENT_JOB_H_
#define CONTENT_BROWSER_ANDROID_URL_REQUEST_CONTENT_JOB_H_

#include <stdint.h>

#include <string>
#include <vector>

#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "content/common/content_export.h"
#include "net/base/net_errors.h"
#include "net/http/http_byte_range.h"
#include "net/url_request/url_request.h"
#include "net/url_request/url_request_job.h"

namespace base {
class TaskRunner;
}

namespace net {
class FileStream;
}

namespace content {

// A request job that handles reading content URIs
class CONTENT_EXPORT URLRequestContentJob : public net::URLRequestJob {
public:
    URLRequestContentJob(
        net::URLRequest* request,
        net::NetworkDelegate* network_delegate,
        const base::FilePath& content_path,
        const scoped_refptr<base::TaskRunner>& content_task_runner);

    // net::URLRequestJob:
    void Start() override;
    void Kill() override;
    int ReadRawData(net::IOBuffer* buf, int buf_size) override;
    bool IsRedirectResponse(GURL* location, int* http_status_code) override;
    bool GetMimeType(std::string* mime_type) const override;
    void SetExtraRequestHeaders(const net::HttpRequestHeaders& headers) override;

protected:
    ~URLRequestContentJob() override;

private:
    // Meta information about the content URI. It's used as a member in the
    // URLRequestContentJob and also passed between threads because disk access is
    // necessary to obtain it.
    struct ContentMetaInfo {
        ContentMetaInfo();
        // Flag showing whether the content URI exists.
        bool content_exists;
        // Size of the content URI.
        int64_t content_size;
        // Mime type associated with the content URI.
        std::string mime_type;
    };

    // Fetches content URI info on a background thread.
    static void FetchMetaInfo(const base::FilePath& content_path,
        ContentMetaInfo* meta_info);

    // Callback after fetching content URI info on a background thread.
    void DidFetchMetaInfo(const ContentMetaInfo* meta_info);

    // Callback after opening content URI on a background thread.
    void DidOpen(int result);

    // Callback after seeking to the beginning of |byte_range_| in the content URI
    // on a background thread.
    void DidSeek(int64_t result);

    // Callback after data is asynchronously read from the content URI into |buf|.
    void DidRead(int result);

    // The full path of the content URI.
    base::FilePath content_path_;

    std::unique_ptr<net::FileStream> stream_;
    ContentMetaInfo meta_info_;
    const scoped_refptr<base::TaskRunner> content_task_runner_;

    net::HttpByteRange byte_range_;
    net::Error range_parse_result_;
    int64_t remaining_bytes_;

    bool io_pending_;

    base::WeakPtrFactory<URLRequestContentJob> weak_ptr_factory_;

    DISALLOW_COPY_AND_ASSIGN(URLRequestContentJob);
};

} // namespace content

#endif // CONTENT_BROWSER_ANDROID_URL_REQUEST_CONTENT_JOB_H_
